1. Field of the Invention
The present invention relates to a light emission control device such as an LED (light-emitting diode) driver IC, and to a display device incorporating such a light emission control device. The invention also relates to a drive control device for supplying a predetermined drive current to a load, and to a control device that changes its output state according to a control signal.
2. Description of Related Art
A conventional light emission control device for supplying a drive current to a light-emitting element such as an LED typically employs a two- or more-line interface as a control interface so that, as commands, such as those requesting writes to a register, are transmitted to the light emission control device, its turning-on and -off and light emission amount (drive current level) are controlled.
A conventional technology related to the present invention is disclosed, for example, in JP-A-2002-335234 (a single-line serial data transfer method and a data transfer interface circuit employing it).
Certainly, with conventional light emission control devices as described above, it is possible to control their turning-on and -off and light emission amount (driving current level) according to various control signals fed from outside the device.
Inconveniently, however, with the conventional light emission control devices described above, the control signal needed to control their turning-on and -off and the control signal needed to control their light emission amount (driving current level) are fed in via separate control interfaces. This complicates the control and also requires an increased number of external terminals, leading to an increased size and cost of light emission control devices (and hence of display devices employing them).
Incidentally, there have been proposed various system control technologies employing a single-line interface, like the single-line serial data transfer method disclosed in JP-A-2002-335234 mentioned above. Any of these conventional technologies, however, differs in essence from the present invention described herein.